I really like this romper...I'm 5'4" 115 Lbs and usually wear anywhere from a XS to a Small...I got the XS and it fits to a T. If you know Wildfox then you know that their clothing fits a little larger than most so you can get your typical size for a loose fit or go a bit smaller for something more fitted. Great purchase all around and I look forward to wearing it in Mexico next week!